Conventional sport shooting target designs include the standard clay pigeon designs as well as other flying targets and a rabbit design which hops as it rolls across the ground.
Typical sporting clay targets are made by molding a black composite of tar pitch and powdered limestone (calcium carbonate) and painting them bright colors for visibility. These targets are strong enough to be thrown by a machine, but frangible enough to break when hit with one or two pellets from a shot gun.
It is generally recognized that these conventional targets are toxic when eaten by animals and that they do not biodegrade or decompose, consequentially they quickly leave large amounts of unsightly residue in hard to clean areas of sporting clay courses.
Several attempts have been made to develop biodegradable clay pigeons to solve the toxicity and residue problems. Two known solutions include ice targets and targets using starch type binders. However, ice targets must be manufactured close to the point of use to be practical for sporting clay courses and have not found practical application because of the slow complex processes required to produce them. Starch based targets soften under high humidity conditions and become unusable.